#nav-left, #nav-right {
  height: 22px; 
  width:  112px;
  padding: 0;
}
#nav-left {
    background: url("../image/prevnext.png") no-repeat scroll center -22px transparent;
}
#nav-right {
    background: url("../image/prevnext.png") no-repeat scroll center -66px transparent;
}
#nav-left:hover {
    background: url("../image/prevnext.png") no-repeat scroll center 0 transparent;
}
#nav-right:hover {
    background: url("../image/prevnext.png") no-repeat scroll center -44px transparent;
}